I would advise people who rescue large pets to be sure that they have a facility which will take the pet off their hands. It is an awesome responsibility to rescue an animal because of the expense and inconvenience it sometimes presents. Try to be sure you have the needed resources and emotional stamena it takes to do such a thing.
Be sure your financial resources are abundant because, unfortunately, that sometimes runs out before your caring and concern. Regards.
P.S. I respect your ambition and for the animal's sakes, I wish you only the best.